This invention relates to an adhesive copolymer microspheres-containing aqueous suspension which is usable as an adhesive for an adhesive sheet or tape, and particularly relates to a repeatedly usable and releasable adhesive sheet or tape which allows a step of bonding the adhesive sheet or tape to a substrate and a step of removing the sheet or tape from the substrate to be repeatedly carried out.
U.S. Pat. No. 3,691,140 dated Sept. 12, 1972 by Silver and U.S. Pat. No. 4,166,152 dated Aug. 28, 1979 by Baker et al disclose infusible, solvent-dispersible, solvent-insoluble, inherently tacky, elastomeric copolymer microspheres. The Silver and Baker et al patents also disclose that the copolymers are dispersed in solvents, followed by spraying the resulting solution of the copolymers on a substrate and that the copolymers permit bonding of paper and other materials to various substrates and permit easy removal of bonded paper from the substrate without tearing. However, in the processes of Silver and Baker et al, the monomeric components are polymerized in the absence of a protection colloid. Therefore, it was found that when the adhesives obtained from the copolymer microspheres of the Silver and Baker et al patents are coated on paper and dried, the resulting adhesive-coated paper is not a coated paper which can be repeatedly used and released.